Germination test in carioca bean seeds chemically treated with the use of alternative substrates / Teste de germinação em sementes de feijão carioca tratadas quimicamente com uso de substratos alternativos

The use of quality seeds is a key element for the success of carioca bean (Phaseolus vulgaris L.) cultivation. To avoid or reduce various problems of importance to the crop, it facilitates the achievement of the cultivar's productive potential and the reduction of production costs. Thus, the objective of this work is to identify which conditions are suitable for evaluating germination in bean seeds using different substrates. The treatments were subjected to a temperature of 25°C analyzing five substrates (germitest® paper; germitest® paper + sand; germitest® paper + soil; germitest® paper + charcoal and germitest® paper + vermiculite). The chemicals used were: Cruiser 350 FS, Fortenza 600 FS, Standak Top and Avicta complete. The most suitable substrate for installing the germination test in beans depends on the type of product and active ingredient of the seed treatment. Emphasizing the substrates germitest® + vermiculite and germitest®+soil, those that best performed positive characteristics when in contact with the chemical treatment.

O uso de sementes de qualidade é um elemento chave para o sucesso dos cultivos do feijão carioca (Phaseolus vulgaris L.). Por ser uma forma de evitar ou reduzir problemas diversos de importância para a cultura, facilita a obtenção do potencial produtivo da cultivar e a redução de custos de produção. Tendo assim, como objetivo esse trabalho identificar quais as condições adequadas para avaliação da germinação em sementes de feijão através da utilização de diferentes substratos. Os tratamentos foram submetidos a temperatura de 25°C analisando cinco substratos (papel germitest®; papel germitest® + areia; papel germitest® +solo; papel germitest®+ carvão e papel germitest® + vermiculita). Os produtos químicos utilizados foram: Cruiser 350 FS, Fortenza 600 FS, Standak Top e Avicta completo. O substrato mais indicado para instalação do teste de germinação em feijão depende do tipo de produto e ingrediente ativo do tratamento de sementes. Destacando os substratos germitest® + vermiculita e germitest®+solo, os que melhor desempenharam características positivas quando em contato com o tratamento químico.

Mobilization of seed storage proteins is crucial to high vigor in common bean seeds / Mobilização das proteínas de reserva é crucial para o alto vigor em sementes de feijão

Seed germination is a complex process controlled by many factors, in which physical and biochemical mechanisms are involved and the mobilization of reserves is crucial for this process to occur. Although, seed reserve mobilization is usually thought to be a post-germination process, seed reserve proteins mobilization occurs during germination. This study quantified seed proteins of bean genotypes during different hydration times, in order to understand the process of protein mobilization and whether there is relationship of this biochemical component with seed vigor. This study was conducted using seeds with different levels of vigor, genotypes with highest (13, 42, 55 and 81) and lowest (07, 23, 44, 50, IPR-88-Uirapurú and Iapar 81) physiological quality. High vigor genotypes showed greater efficiency in hydrolysis and mobilization of protein component, because they presented low globulins content in cotyledons at radicle protrusion in relation to low vigor genotypes (07, 23 and 50). The protein alpha-amylase inhibitor, observed in all genotypes, is involved with the longer time needed for radicle protrusion, according to the band intensity difference in genotypes 07, 44 and Iapar 81.

A germinação de sementes é um processo complexo controlado por muitos fatores, nos quais mecanismos físicos e bioquímicos estão envolvidos e a mobilização de reservas é decisiva para que esse processo ocorra. Embora a mobilização de reservas de sementes seja considerada um processo pós-germinativo, a mobilização das proteínas de reserva de sementes ocorre durante a germinação. Este estudo teve como objetivo quantificar as proteínas de sementes de genótipos de feijão durante os diferentes tempos de hidratação, a fim de compreender o processo de mobilização proteica e se há relação desse componente bioquímico com o vigor das sementes. Este estudo foi realizado utilizando sementes com diferentes níveis de vigor, genótipos com maior (13, 42, 55 e 81) e menor (07, 23, 44, 50, IPR-88-Uirapurú e Iapar 81) qualidade fisiológica. Os genótipos de alto vigor apresentaram maior eficiência na hidrólise e mobilização do componente proteico, pois apresentaram baixo teor de globulinas nos cotilédones na protrusão radicular em relação aos genótipos de baixo vigor (07, 23 e 50). A proteína inibidora da alfa-amilase, observada em todos os genótipos, está envolvida com o maior tempo necessário para a protrusão da radícula, de acordo com a diferença de intensidade da banda nos genótipos 07, 44 e Iapar 81.

Dynamics of abscission of reproductive structures in common bean access / Dinâmica da abscisão de estruturas reprodutivas em acessos de feijoeiro comum

Genotypes from the Andean and Mesoamerican gene pool can present contrasting behavior for reproductive structures fixation. The subject of this study was to determine the dynamics associated with the abscission of reproductive structures for common bean accesses from Andean and Mesoamerican gene pools in protected cultivation conditions. The experiment was carried out in a greenhouse, using seven common bean accesses from Embrapa Arroz e Feijão and the experimental design consisted of a randomized complete block design. The evaluations made were based on the number of days to begin flowering, flowering period, number of emitted flowers per plant, number of flower buds, flowers and pods aborted per plant, total number of pods per plant and number of seeds per plant.Certain characteristics were considered to be highly significant, such as the amount of days to begin flowering, the flowering period, percentage of aborted pods and number of harvested pods. The Mesoamerican accesses that presented greater abortion also produced more flowers, which suggests that abortion of reproductive structures can be a natural adjustment of the plant. Andean accessions with shorter reproductive period showed greater pod abortion. The dynamics of flower and pod abscission in the common bean proved to be widely variable depending on the different gene pools and genotypes evaluated and due to growth

Genótipos do pool gênico andino e mesoamericano podem apresentar comportamentos contrastantes para a fixação de estruturas reprodutivas. O objetivo deste estudo foi determinar a dinâmica associada à abscisão de estruturas reprodutivas para acessos de feijoeiro comum dos pools gênicos andino e mesoamericano em condições de cultivo protegido. O experimento foi conduzido em casa de vegetação, utilizando-se sete acessos de feijoeiro da Embrapa Arroz e Feijão e o delineamento experimental foi em blocos casualizados. As avaliações feitas foram o número de dias para o início da floração, período de floração, número de flores emitidas por planta, número de botões florais, flores e frutos abortados por planta, número total de frutos por planta e número de sementes por planta. Observou-se significância para as características de dias para início do florescimento, período de floração, porcentagem de vagens abortadas e número de vagens colhidas. Os acessos mesoamericanos que apresentaram maior aborto também produziram mais flores, o que sugere que o aborto de estruturas reprodutivas pode ser um ajuste natural da planta. Acessos andinos com menor período reprodutivo, apresentaram maior aborto de frutos. A dinâmica de abscisão da flor e da vagem no feijoeiro mostrou-se amplamente variável dependendo dos diferentes pools gênicos e genótipos avaliados, devido ao hábito de crescimento.

Dynamics of abscission of reproductive structures in common bean access / Dinâmica da abscisão de estruturas reprodutivas em acessos de feijoeiro comum

Genotypes from the Andean and Mesoamerican gene pool can present contrasting behavior for reproductive structures fixation. The subject of this study was to determine the dynamics associated with the abscission of reproductive structures for common bean accesses from Andean and Mesoamerican gene pools in protected cultivation conditions. The experiment was carried out in a greenhouse, using seven common bean accesses from Embrapa Arroz e Feijão and the experimental design consisted of a randomized complete block design. The evaluations made were based on the number of days to begin flowering, flowering period, number of emitted flowers per plant, number of flower buds, flowers and pods aborted per plant, total number of pods per plant and number of seeds per plant.Certain characteristics were considered to be highly significant, such as the amount of days to begin flowering, the flowering period, percentage of aborted pods and number of harvested pods. The Mesoamerican accesses that presented greater abortion also produced more flowers, which suggests that abortion of reproductive structures can be a natural adjustment of the plant. Andean accessions with shorter reproductive period showed greater pod abortion. The dynamics of flower and pod abscission in the common bean proved to be widely variable depending on the different gene pools and genotypes evaluated and due to growth(AU)

Genótipos do pool gênico andino e mesoamericano podem apresentar comportamentos contrastantes para a fixação de estruturas reprodutivas. O objetivo deste estudo foi determinar a dinâmica associada à abscisão de estruturas reprodutivas para acessos de feijoeiro comum dos pools gênicos andino e mesoamericano em condições de cultivo protegido. O experimento foi conduzido em casa de vegetação, utilizando-se sete acessos de feijoeiro da Embrapa Arroz e Feijão e o delineamento experimental foi em blocos casualizados. As avaliações feitas foram o número de dias para o início da floração, período de floração, número de flores emitidas por planta, número de botões florais, flores e frutos abortados por planta, número total de frutos por planta e número de sementes por planta. Observou-se significância para as características de dias para início do florescimento, período de floração, porcentagem de vagens abortadas e número de vagens colhidas. Os acessos mesoamericanos que apresentaram maior aborto também produziram mais flores, o que sugere que o aborto de estruturas reprodutivas pode ser um ajuste natural da planta. Acessos andinos com menor período reprodutivo, apresentaram maior aborto de frutos. A dinâmica de abscisão da flor e da vagem no feijoeiro mostrou-se amplamente variável dependendo dos diferentes pools gênicos e genótipos avaliados, devido ao hábito de crescimento.(AU)

Creole bean seeds microbiolization with doses of Trichoderma harzianum / Microbiolização de sementes de feijão crioulo com doses de Trichoderma harzianum

In the search for improved yields, seed treatment by microbiolization has been used as an alternative to chemical treatment. The objective was to verify the physiological and sanitary quality of creole bean seeds, var. Chumbinho, after microbiolization with doses of a commercial product (c.p.) with Trichoderma harzianum (strain ESALQ-1306). The treatments were: T1) 100 mL c.p./100 kg seeds; T2) 150 mL c.p.; T3) 200 mL c.p.; T4) 200 mL of chemical treatment (c.p., 250 g L-1 fipronil + 25 g L-1 pyraclostrobin + 225 g L-1 thiophanate-methyl); and T5) control (without coating of seeds). The tests were: sanitary test (blotter test); germination and first count; accelerated aging, cold germination without soil, speed of germination rate (SGR), seedling shoot and root lengths, and emergence of seedlings in a greenhouse. T. harzianum controlled Aspergillus spp., Penicillium spp. and Fusarium oxysporum. With 100 mL c.p. of T. harzianum dose had better results for the germination and vigor, and this dose it is an alternative to chemical treatment in creole bean seeds.(AU)

Na busca por melhores rendimentos, o tratamento de sementes por microbiolização tem sido utilizado como alternativa ao tratamento químico. Objetivou-se verificar a qualidade fisiológica e sanitária de sementes de feijão crioulo, var. Chumbinho, após microbiolização com doses de um produto comercial (p.c.) com Trichoderma harzianum (cepa ESALQ-1306). Os tratamentos foram: T1) 100 mL p.c./100 kg de sementes; T2) 150 mL p.c.; T3) 200 mL p.c.; T4) 200 mL tratamento químico (p.c., 250 g L-1 fipronil + 25 g L-1 piraclostrobina + 225 g L-1 tiofanato metílico); e T5) controle (sem revestimento de sementes). Os testes foram: sanidade (blotter test), germinação, primeira contagem, envelhecimento acelerado, teste de frio sem solo, índice de velocidade de germinação (IVG), comprimento de parte aérea e de raiz das plântulas e emergência em casa de vegetação. T. harzianum controlou Aspergillus spp., Penicillium spp. e Fusarium oxysporum. A dose 100 mL de p.c. teve melhores resultados para germinação e vigor, sendo que essa dose é uma alternativa ao tratamento químico em sementes de feijão crioulo.(AU)

Somatic Embryogenesis in Common BeanPhaseolus vulgaris L.

Common bean Phaseolus vulgaris L. has been shown to be a recalcitrant plant to induce somatic embryogenesis (SE) under in vitro conditions. An alternative strategy to yield SE is based upon the use of a cytokinin (benzyladenine) coupled with osmotic stress adaptation instead of the auxin-inducing SE in common bean. Here we described the induction of proembryogenic masses (PEM) derived from the apical meristem and cotyledonary zone of zygotic embryos, from which secondary SE indirect embryogenesis emerged. Maturation of SE was achieved by using osmotic stress medium and converted to plants. Long-term recurrent SE was demonstrated by propagation of PEM at early stages of SE. This protocol is currently being applied for stable genetic transformation by means of Agrobacterium tumefaciens and biobalistics as well as basic biochemical and molecular biology research.

Purification, biochemical characterization, and bioactive properties of a lectin purified from the seeds of white tepary bean (phaseolus acutifolius variety latifolius).

The present work shows the characterization of Phaseolus acutifolius variety latifolius, on which little research has been published, and provides detailed information on the corresponding lectin. This protein was purified from a semi-domesticated line of white tepary beans from Sonora, Mexico, by precipitation of the aqueous extract with ammonium sulfate, followed by affinity chromatography on an immobilized fetuin matrix. MALDI TOF analysis of Phaseolus acutifolius agglutinin (PAA) showed that this lectin is composed of monomers with molecular weights ranging between 28 and 31 kDa. At high salt concentrations, PAA forms a dimer of 63 kDa, but at low salt concentrations, the subunits form a tetramer. Analysis of PAA on 2D-PAGE showed that there are mainly three types of subunits with isoelectric points of 4.2, 4.4, and 4.5. The partial sequence obtained by LC/MS/MS of tryptic fragments from the PAA subunits showed 90-100% identity with subunits from genus Phaseolus lectins in previous reports. The tepary bean lectin showed lower hemagglutination activity than Phaseolus vulgaris hemagglutinin (PHA-E) toward trypsinized human A and O type erythrocytes. The hemagglutination activity was inhibited by N-glycans from glycoproteins. Affinity chromatography with the immobilized PAA showed a high affinity to glycopeptides from thyroglobulin, which also has N-glycans with a high content of N-acetylglucosamine. PAA showed less mitogenic activity toward human lymphocytes than PHA-L and Con A. The cytotoxicity of PAA was determined by employing three clones of the 3T3 cell line, demonstrating variability among the clones as follows: T4 (DI50 51.5 µg/mL); J20 (DI50 275 µg/mL), and N5 (DI50 72.5 µg/mL).

Germination behavior, biochemical features and sequence analysis of the RACK1/arcA homolog from Phaseolus vulgaris.

Partial peptide sequence of a 36 kDa protein from common bean embryo axes showed 100% identity with a reported beta-subunit of a heterotrimeric G protein from soybean. Analysis of the full sequence showed 96.6% identity with the reported soybean G(beta)-subunit, 86% with RACK1B and C from Arabidopsis and 66% with human and mouse RACK1, at the amino acid level. In addition, it showed 85.5, 85 and 83% identities with arcA from Solanum lycopersicum, Arabidopsis (RACK1A) and Nicotiana tabacum, respectively. The amino acid sequence displayed seven WD40 domains and two sites for activated protein kinase C binding. The protein showed a constant expression level but the mRNA had a maximum at 32 h post-imbibition. Western immunoblotting showed the protein in vegetative plant tissues, and in both microsomal and soluble fractions from embryo axes. Synthetic auxin treatment during germination delayed the peak of RACK1 mRNA expression to 48 h but did not affect the protein expression level while the polar auxin transport inhibitor, naphtylphtalamic acid had no effect on either mRNA or protein expression levels. Southern blot and genomic DNA amplification revealed a small gene family with at least one member without introns in the genome. Thus, the RACK1/arcA homolog from common bean has the following features: (1) it is highly conserved; (2) it is both soluble and insoluble within the embryo axis; (3) it is encoded by a small gene family; (4) its mRNA has a peak of expression at the time point of germination stop and (5) its expression is only slightly affected by auxin but unaffected by an auxin transport blocker.